I. Field
The present disclosure relates generally to communication, and more specifically to techniques for accessing a wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various communication content such as voice, video, packet data, messaging, broadcast, etc. These wireless systems may be multiple-access systems capable of supporting multiple users by sharing the available system resources. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal FDMA (OFDMA) systems, and Single-Carrier FDMA (SC-FDMA) systems.
A wireless communication system may include any number of base stations that can support communication for any number of user equipments (UEs). Each UE may communicate with one or more base stations via transmissions on the downlink and uplink. The downlink (or forward link) refers to the communication link from the base stations to the UEs, and the uplink (or reverse link) refers to the communication link from the UEs to the base stations.
A UE may transmit a random access preamble (or an access probe) on the uplink when the UE desires to gain access to the system. A base station may receive the random access preamble and respond with a random access response (or an access grant) that may contain pertinent information for the UE. Uplink resources are consumed to transmit the random access preamble, and downlink resources are consumed to transmit the random access response. Furthermore, the random access preamble and other signaling sent for system access may cause interference on the uplink. There is therefore a need in the art for techniques to efficiently transmit the random access preamble and signaling for system access.